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fEarful™ 12/6 & 15/6 enclosure designs - FREE! (Part V) On with the Madness!

Discussion in 'Amps and Cabs [BG]' started by Chef, Dec 27, 2009.


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  1. davio

    davio

    Nov 2, 2006
    Boston, MA
    Nice, Jim! Excellent intro tutorial. Maybe you could cut and paste that into the wiki at the bottom of the crossover section.
     
  2. greenboy

    greenboy

    Dec 18, 2000
    remote mountain cabin Montana
    greenboy designs: fEARful, bassic, dually, crazy88 etc
    For my tastes that seems as thick as you'd ever want to be in a smaller enclosure. I tend to use around 2" (5 cm). But since it isn't that dense there's some room for interpretation ; }. Anyway, it doesn't really impact internal space as seen by port tuning - it just deadens back-wave midrange reflections from coming back at the cone with so much energy. Which leads to -

    It's pretty subtle and somewhat open to one's one taste. Once you've heard the effects of internal damping a few times after playing the same cabs without damping, you begin to get an idea of how much is enough. Using too much at some point becomes obvious because the cab has gone from being overly lively to actually seeming to have an overly "anechoic" vibe. If you've ever been in an excessively dead studio control room you'll know what I mean. With a lot of enclosures I've done this as a progressive excercise, starting with none, and listening to changes. A few PA boxes I've actually overdone, and later went back and took a little out.

    But with fEarfuls it's not much of an issue in the woofer chamber anyway, since at some point the dedicated, sealed-chamber mid driver is taking over. That's the one to be more concerned about. It's important to stuff the midrange chamber enough to fill it well but not with excessive compression. You don't want fill threatening to press/expand forward into the back of the cone, and you want the motor to have a little breathing space.
     
  3. Swift713

    Swift713

    Dec 4, 2006
    Florence, Ma
    I agree with Greenboy as far as visual aesthetics go. Here's my 12/6 from it's debut gig back last June, plus a closer shot. No tolex, paint, or even grill at that point. The thing sounds great and that's what it there for. I've never seen an ugly amp, ugly basses sure but amps are purely functional from my perspective.
     

    Attached Files:

  4. Passinwind

    Passinwind I Know Nothing Supporting Member Commercial User

    Dec 3, 2003
    Columbia River Gorge, WA.
    Owner/Designer &Toaster Tech Passinwind Electronics
    +1

    Flat black Krylon has always option #1 once my stuff gets really beaten up or needs to find a new home. But my wife has veto power for all the DIY gear residing in our living room, which at present entails something like eight speaker cabs. Clear coat? Yes dear, now what's for lunch?

    I like pie.:cool:
     
  5. Passinwind

    Passinwind I Know Nothing Supporting Member Commercial User

    Dec 3, 2003
    Columbia River Gorge, WA.
    Owner/Designer &Toaster Tech Passinwind Electronics
    Nope. A lot of people throw my name around in relation to commercial builds and whatnot, and I want to stay well clear of that minefield.

    I think the schematic for "my" crossover is probably still in this mega-thread somewhere and someone posted a supposedly dead link in the WIKI that seemed to still work too. When 4Mal gets his Greenboy Cheap But Good design built up we will compare them mercilessly, I'm sure. But I get what I want out of what I have, and I'm happy to have kept things moving in generally the right direction when so many people were holding off on building due to the perceived hassle of rolling their own.

    I mod damn near everything anyway-- always have. If I were doing this anew it would likely be completely different, but sometime a guy's just got to say "enough." ;)
     
  6. Passinwind

    Passinwind I Know Nothing Supporting Member Commercial User

    Dec 3, 2003
    Columbia River Gorge, WA.
    Owner/Designer &Toaster Tech Passinwind Electronics
    Jah, mon. I can think of few things I despise as much as woodworking. But I've been soldering for nearly 50 years at this point, and have rebuilt amps during set breaks when necessary, without thinking twice about it. That's what makes a DIY community interesting to me, diversity.
     
  7. Foz

    Foz

    Jul 26, 2008
    Jax FL USA
  8. Foz

    Foz

    Jul 26, 2008
    Jax FL USA
    GB:

    A modest proposal... start a Paypal account for test equipment donations so the Fearful build community can pool our money toward this acquisition. I'd toss in a couple of sawbucks to get things rolling if you care to set such an account up.

    Its only a thousand bucks - or put another way - 50 guys with $20 each acting in enlightened self interest. :hyper:
     
  9. Passinwind

    Passinwind I Know Nothing Supporting Member Commercial User

    Dec 3, 2003
    Columbia River Gorge, WA.
    Owner/Designer &Toaster Tech Passinwind Electronics
    How about a DIY speaker measurement system thread then, seriously ? I'd be happy to help get it rolling, even though I think my speaker building days are nearly done at this point.
     
  10. Nordskov

    Nordskov

    Apr 26, 2007
    Denmark
    IME a "cold" solder join seldom comes from not applying enough heat but from a shaking hand.
    It's mandatory to have a steady hand while soldering, the slightest jitter while the solder is cooling and you have that "cold" solder join.
    Use a "third" hand.
    Practice makes perfect.

    When I solder I use to wet the tip with a fair blob of solder to fasten heat transfer to the object, then I hold the solder against the other side of the object until it starts flowing. Use only just enough solder to fill the gap.



    There is nothing about these cabs that can't be done by a non-pro. Don't let the woodwork or the electronic circuits scare you off.

    For the woodwork a circular saw and an electric jigsaw will take you far. A tablesaw is faster but not necessairy.
    Ad a handfull of clamps, some glue and a screwdriver and you are good to go.

    Interceptor made a good tutorial for the soldering and if you just take it slowly, assembling the crossover will be a walk in the park.
    Take a look at Bill Fitzmaurices forum, there are several examples of how to do the layout.
    Test it with a multimeter for short circuits and then with your amp at low volumes.
     
  11. BurningSkies

    BurningSkies CRAZY BALDHEAD

    Feb 20, 2005
    Seweracuse, NY
    Again, for any of those who have fears of doing your crossover, please please please don't let it stop you from doing this cab.

    I've done basic soldering over the years, pickups, bass & guitar electronics and cables. That's it. If I can do this crossover, then you can too. Take your time, work over the diagrams carefully, and then do it. Really, its not more than an hour (or two if you're very careful and taking lots of time).

    If anyone wants to trade woodwork for a crossover, etc. let me know. I'd love a 15sub, and have no gear for doing any woodwork. I'll be happy to order up the parts and assemble a crossover.

    Speaking of which, anyone with a 12/6, I have the Eminence 2-way at 800hz sitting on my computer desk that won't ever get used.
     
  12. Marcocolo

    Marcocolo

    Sep 10, 2008
    Fairfield,Iowa
    In the 15/6 setup, do you need to have a heatsink under the resistors? I'm using the expensive ones in your design. Thanks.
     
  13. BurningSkies

    BurningSkies CRAZY BALDHEAD

    Feb 20, 2005
    Seweracuse, NY
    No heat sinks necessary, but do give them enough space to get decent airflow around them (that 3015 will certainly keep the air moving in the cab). If you do want to make sure there's enough air flow 'in case of' put a few washers or spacers in between your mounting board and the resistors when you screw or bolt them down.
     
  14. ::::BASSIST::::

    ::::BASSIST:::: Progress Not Perfection.

    Sep 2, 2004
    Vancouver, BC Canada
    I currently have the LDS 15/6 version and like the tone, but I do find the form factor a little awkward to carry. The GB fEarful tall shaped box is likely easier to carry. I also want to hear what a 'true' fEarful sounds like. I will a/b them and sell the one that is less tonally pleasing and harder to carry. I think its very likely I'll be keeping the fEarful design.

    Would there be any negatives from having the 15" driver mounted near the top and mid driver near the bottom? I am thinking that on small stages (which I play often) I can tilt back the cab on a wedge or ampstand. With the 15 near the top of the cab, I'd likely hear the cab better right? So far I have not been using the mid driver all that much as I dont like alot of highs in my tone. The LDS version has a dial to turn the mid driver up or down. Usually I have it between off and 9:00.
     
  15. rpsands

    rpsands

    Jul 6, 2007
    Phoenix, AZ
    Mid driver on top and use Greenboy's crossover.

    The 15 is going to be crossed over so low you will absolutely use the mid driver that way.

    With the one you have the crossover is much higher I believe (1200hz) so the mid driver will be used less as is.

    Even with the LDS crossover 9 o'clock is probably only around 3db of extra attenuation. Check with Don/Ralf to be sure but I believe the way he wires them is they only add around 3db of extra attenuation max.
     
  16. davio

    davio

    Nov 2, 2006
    Boston, MA
    As has been said previously (assuming I understand this correctly), turning the mid off via variable L-pad is a dangerous idea and can blow components if used like that for prolonged periods of time. From what has been said, use of a variable L-pad isn't a very good idea in the first place since they are not accurate or smooth in adjustment.

    If what rpsands said about your crossover point is true, you'll likely notice a huge difference in tone and "EQ-ability" once you have a legit fEarful on your hands. Having the mid on top is definitely preferable.
     
  17. Interceptor

    Interceptor Supporting Member

    Mar 29, 2005
    Madison, WI
    Thank you for the feedback on the soldering piece. Very appreciated.

    I'm happy to have that as a WIKI article. I'm just not motivated to learn WIKI editing right now. If some kind soul could publish it, that would be very cool.

    I'm deep into research on composite construction. At the rate things are going, I see a 'glass fEarful in my future. One of the guys I hang with is an aerospace engineer who is going to take me to school on foam core construction. This ought to be fun, a aerospace guy trying to ram chemistry into an electronics guy.

    I see a sub 30 pound 15 6 in my future...

    What ever I learn in the process I'll document well. I'm just going to need help once it all gets to publishing stage. Funny part it that doesn't bother me one bit. Can't know everything.

    So, I need a WIKI editor, any volunteers?

    Jim
     
  18. ::::BASSIST::::

    ::::BASSIST:::: Progress Not Perfection.

    Sep 2, 2004
    Vancouver, BC Canada
    Interesting.

    I really like how the LDS 15.6 sounds with the mid driver off or close to it, but I have not had it out more than a handful of times and those were rehearsals. However, I can't help but think that the mid driver will be very necessary to help me cut thru with this 115 cab design. Sometimes I find the tone I prefer 'difficult'. Since I use flatwounds and Model Js (read very little high mids) I rely on the cut of my ul112s to hear myself (sometimes I bump up the upper bass... around 70hz). Naturally, a 115, and especially the fEarful with its girth, will not cut thru as well. It also helps that my 112 stack is fairly tall and close to my ears.

    That said, given that my tone is shy in the treble and high-mid regions, how well will the GB fEarful 15/6 cut thru the mix in my situation?
     
  19. Swift713

    Swift713

    Dec 4, 2006
    Florence, Ma
    Bassist, a couple of your posts mention the "girth" of the fEarful cabs. IME they are, and were designed to be, just plain accurate. They are capable of reproducing a lot of low end but they don't have an inherent tone of their own. It sounds like the LDS 15.6 is a pretty different animal. Other cabs may tend to have more of a mid hump and the fEarfuls may seem scooped in comparison so you may find yourself using your tone controls differently or you may find your bass sitting differently in the mix. I've found I can cut through or slide under with my 12/6 as I please whereas in the past I either cut with a 12 or had mud with a 15. In other words, the fEarful 15/6 should be able to do whatever you want.
     
  20. ::::BASSIST::::

    ::::BASSIST:::: Progress Not Perfection.

    Sep 2, 2004
    Vancouver, BC Canada
    Cool.

    With VLE (similar to a P bass tone knob) at about 9:00 and the VPF (scoop knob) at about 8:00 (everything else flat) on my LMII the lows of the LDS are very fat. Sounds awesome, but may be too much of a 'good' thing on boomy stages, which I seem to encounter often. You know those plywood jobbies that are elevated about a foot off the ground.

    "Accurate" would likely be better.
     



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